This invention is concerned with an apparatus for locating a plurality of angular positions of a rotating member with respect to an angular reference position.
Known are systems for locating angular positions of a rotating member based on detecting a pluality of pulses as determined by particular characteristics of the rotating member as the latter rotates. Such systems require a sensor for sensing an angular reference position and at least another sensor for sensing the other angular positions or fractions of round angle.
It is the object of the present invention to provide a an apparatus for determining the angular positions of a rotating member with respect to a predetermined angular reference, by using a single simple sensor, with resulting benefits in wiring simplicity, reliability and cost.
According to the invention, the system for each revolution of the rotating member consists of providing both an reference signal indicative of the angular reference position, a plurality of position signals, 180.degree. out of phase with the reference signal, each indicative of a different angular position of the rotating member; providing at the second half wave of the bipolar reference signal and position signals a unidirectional reference signal and unidirectional position signals, respectively; converting the unidirectional position signals into logic signals corresponding to the angular positions of the rotating member relative to the reference position; and using the unidirectional reference signal for controlling the cycle repetition.